1. Field of the Invention
The present invention pertains to an automatic water spray control system for fire suppression in the vicinity of underground coal mining machinery and the like.
2. Background
Underground coal mining machines, such as so-called continuous mining-type machines, are typically equipped with an arrangement of water spray nozzles connected to a source of high-pressure water for control of dust and for fire suppression in the event of ignition or eruption of fire in the vicinity of the machine. Underground mining machines, typically, also use electricity as a primary source of power and have hydraulic systems for operating various machine functions and for controlling a dust suppression water spray nozzle array and a fire suppression water spray nozzle array.
One shortcoming of conventional systems is that, in the event of a failure of the electrical power supply system to the mining machine, hydraulically operated control valves will not function to initiate operation of the fire suppression water sprays, in particular. Moreover, if the mining machine is located in an area of the mine which is beyond safe limits of operator access, the machine cannot be reached for manual operation of the water sprays. In this regard, the present invention provides an improved water spray control system which is adapted to operate fire suppression water sprays, in particular, in the event of a failure or shutoff of the electrical power system which would normally also cause a failure or shutdown of a hydraulic fluid power and control system.